Bar for dobby chains



Nov. 25, 1941. w. w. JOHNSTON 2,263,991

BAR FOR DOBBY CHAINS Filed July 22, 1940 INVENTOR 45 WILLIAM JOHNSTON g mma AW 0 RNEY Patented Nov. 25, 1941 omits BAR FOR DOBBY CHAINS William W. Johnston, Worcester, Mass, assignor to Crompton & Knowles Loom Works, Worcester, Mass, a corporation of Massachusetts Application July 22, 1940, Serial No. 346,719

12 Claims.

This invention relates to improvements in bars for dobby loom pattern chains and it is the general object of the invention to provide a bar having improved eyelets or attaching means for the connecting links by which a plurality of bars are assembled to form the pattern chain.

Pattern chains of dobbies usually comprise a series of wooden bars of trapezoidal transverse section having one or two rows of perforations for dobby pegs, depending upon whether the chain is to be used with a single or double index dobby. Each end of the bar has inserted therethrough a wire the ends of which are bent to form eyelets which receive links fitting into corresponding eyelets on adjacent bars. It has been the practice heretofore to bend the wire so that its ends'engage the inclined sides of the bar, the eyelets of any one wire being bent in opposite directions to check the tendency of the wire to rotate on its axis. It is found however, that eyelets formed according to this previous procedure are not sufficiently tight and turn on their axes sufficiently to interfere with proper feeding of the chain over the pattern cylinder and with the assembling of the bars into the chains.

It is an important object of my present inven-' tion to flatten the ends of the wire prior to the formation of the eyelets and force the flattened ends into the sides of the bar. In this way the eyelet is held to the bar not only at the straight part of the wire which extends entirely through the bar but also at the flattened end. By this construction the eyelets are held in fixed relation with respect to the bar.

In the preparation of the bar blank a hole is drilled in the end of the bar for the reception of the wire'which is preferably slightly larger in diameter than the drilled hole. The flattened ends of the wire are preferably so shaped that their thickness is considerably less than the diameter of the wire for thepurpose of reducing any tendency to split the bar which may occur when the flattened ends are forced into it. Any slight amount of wood which may be sheared when inserting the flattened ends will be of less thickness than the wire and will be forced against the latter which prevents transmission of the shearing strains to that part of the bar on the opposite side of the wire.

With these and other objects in view which will appear as the description proceeds, my invention resides in the combination and arrangement of parts hereinafter described and set forth.

In the accompanying drawing, wherein three forms of the invention are set forth,

Fig. 1 is an elevation of a portion of the chain having bars made according to the preferred form of my present invention,

Fig. 2 is a side view of one of the bars shown" in Fig. 1, i

Fig. 3 is an end view looking in the direction;

of arrow 3, Fig. 2, on an enlarged scale,

Fig. 4 is a horizontal section on line 4-4 of Fig. 2 on an enlarged scale,

Fig. 5 is a vertical section on line 5-5 of Fig. 2,

Figs. 6 and '7 are diagrammatic views showing steps in the assembling of the wire on the bar,

Fig. 8 is an enlarged end elevation'of one end of the eyelet forming wire looking in the direc-' tion of arrow 8, Fig. 7,

Figs. 9 and 10 are views similar to Fig. 4 but showing the first and second modified forms of the invention, respectively.

Referring to the drawing, particularly Fig. 1, I have shown a series of bars I!) each of which has eyelets ll located at each end thereof, and links l2 connect adjacent eyelets of adjacent bars. Each bar has a relatively wide base 14' and a narrower top l3'and has inclined sides l5. Extending vertically through the bar .are perforations I6v which receive the dobby pegs I! by means of which indication is given to mechanism not shown but formingpart of the loom dobby for control of thewarp threads in the loom,

not shown. The bars are fed progressively to a controlling position by means of a cylinder not shown and the pegs are arranged in such order as to produce the desired pattern in the fabric being woven. The particular bar shown for instance in Fig. 4 is that employed in the so-called double,

index dobby in which two'parallel rows of perforations extend throughout the length of the bar, while the bar shown index dobby.

Except for the form of the eyelets to be set forth more particularly hereinafter the matter thus far described is of common construction: The bars are preferably made of hard wood and r the wires are formed of a steel which can .be bent to form the eyelets.

In carrying the preferred form of my present invention into efiect I insert a wire 20 into each diameter of the wire and the plane in which'the in Fig. 10 is for a'single blades he is parallel to the top and bottom flat surfaces l3 and I4. The ends of the wire which project beyond the bar are then bent in opposite directions, the upper end as indicated in dotted lines in Fig. 7 being bent to the right while the lower end is bent to the left. The planes of the blades are substantially parallel to the planes of their respective eyes.

Duringthe bending operation the blades are forced into the bar and out small slots in the inclined walls l5, but this slot is of less width than the diameter of the wire and any shearing of the bar along its grain will be resisted by the shank of the wire which extends through the bar, as will be understood from aninspection of Fig. 5. The blades are spaced an appreciable distance from the straight body 30 of the wire and the eyelets are therefore held. in fixed. position with respect to the bar and cannot rotate. The slots 25 are shallow, since it is not necessary to embed the blades very far into the bar to prevent rotation of the eyelets.

In Fig. 9 I show the first modified form of the invention in which only one-end of the wire has a flattened blade 36. In this form all the parts are substantially the same as" those heretofore described except the blunt end which is pressed. close to the wall. adjacent thereto. Inasmuch as one end of the wire-is held at twospaced points asin the preferred form, the

wire will haveno'appreciable tendency to turn on the shank 31 as an axis. It should be noted that as shown in Fig. 9 I prefer to-place the fiat blade on that side of the shank 37 which is opposite the adjacent end of the bar 38. In this way any tendency of. the. blade 36- to split the dobby bar is effectively checked. The: blunt end 40 has-no tendency to split the bar 38 since'it does not enter the bar and. subjects the same to no splittingstrains.

The second modification of my invention is shownin Fig. 10 where. the dobby bar is that used on a. so-called single index dobby and has a single row of peg receiving perforations 46. Extending. through the end of the bar is a wire the shank of which 51' is perpendicular to the axis of the bar instead of diagonal as in. the two forms previously described. The wire has ends which are bent to form eyelets 52' each of which is provided with a blade 53' similar to the blades or flattened ends of the wire already described. These blades are embedded in the bar. 45 and serve the same purpose as do the corresponding blades in the first or second forms of the invention, that is, preventing the eyelets from turning with respect to. the bar.

From the foregoing it will be seen that I have provided a simple dobby her having the eyelets anchored to the bar at two spaced points; thus effectively preventing any tendency for the eyelet' to turn about the axis of the shanks which passthrough the bars. the blades are considerably thinner than the wire on which they are formed and for this reason any shearing or splitting tendencies which.

accompany the forcing of the blades into the bar will be effectively checked by the shanks. The blades are also of a greater width than the diameter of the wire, as shown in Fig. '7, and have flat top and bottom surfaces which di'stribute the resisting force tending to. prevent turning of the wire over. a larger area. than heretofore, thus reducing injury to the. bar and increasing, the tendencyof'the eyelets to maintain their correct alignment with the bar. In actual It will also be seen that" manufacture the radius around which the blades are turning when they enter the bar is relatively short, hence the slots 25 formed by the blades do not extend along the bar sufficiently to cause incipient splitting. It will also be seen that the blades are inserted into the inclined walls a very short distance and that there is sufficient material lying between the two blades of any wire inthe first two forms of the: invention to resist such slight splitting tendency as may be created when they are forced into the bar. With reference to Fig. 9 it will further be seen that I may secure many of the benefits of my invention by using a single blade 36 which is preferably so located that the adjacent end of the wooden bar is protected by the shank 31. While I have used my invention in connection with wooden bars I do not wish to' be limited to this material, as certain features of my invention are equally useful when used with a bar of any material into which. the blades canbe embedded.

Having thus described my inventionit will be seen that changes and modifications may be made therein by those skilled in the art without departing. from the spirit and scope of the invention and I do not wish to-be. limited to the details bar.

herein disclosed, but what I claim is 1. A bar. fora dobby pattern chain of polygonal 7 cross section and having top and bottom parallel faces and having. also a series of peg receiving holes. extendingtherethrough, said bar. having. a wire extending transversely through one end thereof. and. bent to form eyelets on. each side of the bar, the ends of the wire being. flattened to ,form blades which are of less thickness and greater width than the diameter of the Wire, said blades being embedded into the material of the bar with each blade. in a plane substantially parallel to said parallel top and bottom. faces. to prevent turning of the wire with respect to the 2. A bar for a dobby pattern chain of polygonal cross section and having a series. of peg rereceiving holes extending therethrough, said. bar

, I having a wire extending transversely through one end thereof and bent to form eyelets on each side of the bar, at least one end of the wire being flattened to provide a blade of l'essthickness and greater width than the diameter of the wire, said blade being disposed in the plane of the eyelet and embedded into. the bar to prevent turning of the wire with respect to thebar.

3'. A bar for a dobby pattern ch'ainof polygonal cross section and having a series of peg receiving. holes extending therethrough, said bar having a wire extending transversely through one end thereof and bent to form eyelets on each side of the bar, atleast one end of the wi'rebei'ng formed into a flat blade lying substantially in the plane of the corresponding eyeand the blade having a thickness less than the diameter of the wire and a width measured longitudinally of the bar which is? greater than the diameter of the wire, said blade being embedded into the bar to prevent turning of the wire with respect to the bar;

4. A bar for a dobbypattern chain of polygonal cross section and having a series of peg receiving holes extending therethrough, said bar having a wire extending transversely through one end thereof and bent to form eyelets on each side of'the bar; the wire forming one eyelet being bent in a direction away from the. adjacent'end.

of the bar and formed with a. flattened: blade which lies in the plane of'thecorrespond'ing eyelet and is integral with the wire and of less thickness and greater width than the diameter of the wire, said blade extending into the bar on the side of the eyelet opposite the adjacent end of the bar to prevent turning of the wire with respect to the bar.

5. In a bar for a dobby pattern chain having an elongated body formed of wood and having a polygonal cross section, the bar having a series of peg receiving holes, a wire extending through the bar adjacent one end thereof and having the end thereof bent to form eyes, at least one end of the wire being flattened and forced into the wooden body of the bar to be embedded therein and prevent turning of the wire with respect to the bar.

6. In a bar for a dobby pattern chain having an elongated body formed of wood and having a polygonal cross section, the bar having a series of peg receiving holes, a wire extending through the bar adjacent one end thereof and having the end thereof bent to form eyes, at least one end f the wire being formed with a fiat blade of less thickness than the diameter of the wire and forced into the wooden body of the bar to be embedded therein and thereby prevent rotation of the wire with respect to the bar.

'7. In a dobby pattern chain bar having substantially parallel top and bottom surfaces and oppositely beveled longitudinal edges, a wire extending transversely through the bar and said oppositely beveled edges and having the ends thereof bent to form eyelets the planes of which are substantially parallel to and located between the planes of the top and bottom surfaces, at least one end of the wire being formed into a blade disposed in the plane of the corresponding eyelet and having a thickness measured transversely of said planes less than the diameter of the wire and a width measured parallel to said planes greater than the diameter of said wire, said blade projecting inwardly from the adjacent beveled edge and terminating between said beveled edges and having engagement with portions of the bar between said beveled edges to prevent turning of the wire with respect to the bar.

8. In a dobby pattern chain having substantially parallel top and bottom surfaces and oppositely beveled longitudinal edges, a wire extending transversely through the bar and said oppositely beveled edges and having the ends thereof bent to form eyelets the planes of which are substantially parallel to the top and bottom surfaces, at least one end of the wire being fiattened to form a blade of less thickness than the diameter of the wire, the end edge of the blade transverse of the wire projecting into the bar through the adjacent beveled edge and lying in the plane of the adjacent eyelet and terminating between said beveled edges and engaging portions of the bar to prevent rotation of the wire relatively to the bar.

9. The method of forming an eyelet on the end of a dobby pattern chain bar having parallel top and bottom surfaces and edge surfaces, the

method consisting in the following steps: inserting a wire transversely through the bar in a direction parallel to the top and bottom surfaces of the bar, thereafter flattening that end of the wire which was inserted through the barto form a blade on said end of less thickness than the diameter of the wire, bending said one end of the wire to form an eyelet ina plane parallel to said blade and said top and bottom surfaces, and projecting said blade beyond the adjacent edge surface of the bar and into engagement with the bar while the plane of the eyelet is maintained parallel to the top and bottom surfaces of the bar.

10. The method of forming an eyelet on the end of a dobby pattern chain bar having substantially parallel top and bottom surfaces and edge surfaces, the method consisting in the following steps: inserting a wire transversely through the edge surfaces of the bar, flattening that end of the wire which was inserted through the bar to form thereon a blade of less thickness and greater width than the diameter of the wire, bending the flattened end of the wire in such a direction as to form an eyelet the plane of which is parallel to the plane of the blade and the top and bottom surfaces, and projecting the blade through the adjacent edge surface of the bar into engagement with portions of the bar located between said edge surfaces.

11. The method of forming an eyelet on the end of a dobby pattern chain bar having top and bottom parallel surfaces and oblique longitudinal edges, said method consisting in the following steps: inserting a wire transversely through the oblique edges, thereafter flattening that end of the wire which was inserted through the bar to form thereon a blade the thickness of which is less than the diameter of the wire and the width of which is greater than the diameter of the wire, bending the flattened end of the wire to form an eyelet the plane of which is substantially parallel to said top and bottom surfaces and also parallel to the plane of the blade, and projecting the blade through the adjacent oblique edge and into holding relation with respect to parts of the bar located between the top and bottom surfaces of the bar.

12. The method of forming eyelets in the end of a dobby pattern chain bar having top and bottom parallel surfaces and oblique longitudinal edges, said method consisting in the following steps: inserting a wire transversely through an end of the bar and the oblique edges, thereafter flattening the ends of the wire on opposite sides of the bar to form blades the planes of which are parallel, bending the ends of the wire in opposite WILLIAM W. JOHNSTON. 

